DNA interaction and antiproliferative behavior of the water soluble platinum supramolecular squares [(en)Pt(N-N)]4(NO3)8 (en=ethylenediamine, N-N=4,4'-bipyridine or 1,4-bis(4-pyridyl)tetrafluorobenzene)

The interaction with DNA of two water soluble platinum supramolecular squares [(en)Pt(N-N)]4(NO3)8 (en=ethylenediamine, N-N=1,4-bis(4-pyridyl)tetrafluorobenzene, compound 1, N-N=4,4'-bipyridine, compound 2) has been studied by circular dichroism, electrophoretic mobility and atomic force microscopy. the two complexes drastically modify the second and tertiary structures of DNA, but compound 2 does it strongly due probably to its smaller size by comparison with compound 1 and its more suitable structural features for intercalation between base pairs. The two supramolecular squares were assayed against the HL-60 tumor cell line for 24 and 72 h. The IC50 values for 24 h are smaller than that of cisplatin for this time, however for 72 h the IC50 have higher values being the corresponding to compound 2 comparable to that of cisplatin. Apoptotic assays were also carried out for the compounds 1 and 2 against the tumor cell line.